Methanol → HCID 18677067, compound

Participants

Reaction Steps

80 mg (0.22 mmol) 6-(7-acetylamino-2,5-dioxo-1,2,3,5-tetrahydro-benzo[e][1,4]diazepin-4-yl)-hexanoic acid methyl ester was dissolved in 1 ml MeOH/HCl (freshly prepared from 10 ml MeOH and 1 ml SOCl2). The solution was stirred for 18 h and concentrated in vacuo. The residue was taken up in 2 ml of THF/MeOH (1: 1) and 0.5 ml 1N aqueous NaOH was added. After stirring for 16 h at 22° C. the mixture was neutralised by addition of solid carbon dioxide, and the solvents were evaporated. The residue was taken up in DMF (2.5 ml) and 0.032 ml benzylisocyanate (0.26 mmol) was added. The mixture was shaken at 45° C. over night and evaporated. The crude product was purified by preparative HPLC to give 6-[7-(3-benzyl-ureido) -2,5-dioxo-1,2,3,5-tetrahydro-benzo[e][1,4]diazepin-4-yl]-hexanoic acid (19 mg, 0.043 mmol): MS (ISN) 437(M−H)−.

Provenance & Evidence